Estimation of time-varying reproduction numbers of COVID-19 in American countries with regards to non-pharmacological interventions

This study aimed to estimate the basic reproduction number and the time-varying estimate of effective reproductive number  of COVID-19 in American countries as they implemented non-pharmacological strategies for the containment of the SARS-CoV-2 virus. Data sources included COVID-19 epidemic data from Johns Hopkins University’ data repository and official websites of countries with a relatively high incidence of COVID-19. The maximum likelihood method was used to estimate the and . The results showed that El Salvador, the Dominican Republic, Panama, and Peru have the lowest, while the USA and Canada have the highest. Other American countries have an around 1.4. Countries could be divided into three groups based on the varied behavior of  over time. The first group (Mexico, USA, Colombia and Brazil) started with a high, which decreased post-intervention. In the second group, the intervention was performed at the moment when the, is high and it decreased slowly post-intervention (Canada, Argentina, Chile Peru, Panama and Dominican Republic). In the third group (Bolivia, Peru and Guatemala), the, was erratic and could not be attributable to the intervention. There is a close relationship between  and non-pharmacological interventions decreed by governments of countries for the control of the COVID-19 pandemic. There are also immediate changes in the behavior of the indicator, and therefore the progression of the outbreak, when the interventions were implemented closer to the index case for each country.